Gli autori desiderano ringraziare giugno Middleton per la fornitura di E. ceppi faecalis e di orientamento con coltura batterica. C. elegans sono stati forniti dal CGC, che è finanziato dal NIH Ufficio Programmi di un&#39;infrastruttura di ricerca (P40 OD010440).

1) Preparazione di nematodi Crescita media (NGM) <ol><li> Per fare 50 piatti, aggiungere 1,5 g di NaCl, 8,5 g Ultrapure Agar, e 1,25 g peptone a un 1 Lflask. </li><li> Aggiungere 487,5 ml di dH 2 O a pallone. Agitare delicatamente per mescolare e coprire l&#39;apertura del pallone con un pezzo di foglio di alluminio. </li><li> Sterilizzare la soluzione in autoclave a condizioni standard (121 psi, 120 ° C, 20 min). </li><li> Lasciar raffreddare la soluzione a 45 ° C in un bagno d&#39;acqua. </li><li> Per la soluzione, aggiungere quanto segue in ordine: colesterolo 500 microlitri di una 5 mg / ml soluzione madre (disciolto in etanolo), 500 microlitri 1 M CaCl 2, 500 ml 1 M MgSO4, e 12,5 ml KPO 4 tampone (54.15 g KH 2 PO 4 e 17,8 g di K 2 HPO 4 in 500 ml di dH 2 O), come descritto in 18. </li><li> Usando pipette sterili, aggiungere 10 ml di soluzione di agar per ogni polistirolo piastra di Petri di 60 mm. Lasciare i supporti a solidificare a temperatura ambiente overnight. </li></ol> 2) Preparazione di B Brodo E. coli media <ol><li> Per fare cinque culture 100 ml, aggiungere 5,0 g di Bacto Tryptone, 2,5 g di estratto di lievito, 5,0 g di NaCl in un recipiente. </li><li> Aggiungere sterile, acqua distillata fino ad un volume finale di 500 ml. Riscaldare la soluzione su una piastra calda, mescolando, finché i soluti sono dissolti. </li><li> Versare 100 ml di brodo B in cinque bottiglie di vetro (almeno 200 ml di volume). </li><li> Sterilizzare le soluzioni in autoclave a condizioni standard (121 psi, 120 ° C, 20 minuti). </li><li> Lasciare B brodo raffreddare a temperatura ambiente prima dell&#39;uso. </li></ol> 3) Semina C. elegans Piastre di manutenzione <ol><li> Dopo aver lasciato piastre NGM ad asciugare a temperatura ambiente per almeno una settimana, inoculare un 100 ml di brodo di coltura B con alcune colonie di E. coli (OP50). </li><li> Crescere E. coli coltura a 37 ° C per una notte. </li><li> Pipetta di one-two gocce (circa 10081; l) di OP50 cultura sul centro di ciascuna piastra NGM. Le piastre sono in genere accatastati coperchio verso l&#39;alto. Quando pipettaggio (semina), iniziare pipettando cultura sulla piastra in fondo alla pila. Il tuo lavoro su ogni pila. Cercare di non spostare le piastre dopo la semina, poiché è importante che la cultura non diventi troppo vicino ai bordi della lastra. </li><li> Lasciare le piastre seminate ad asciugare a temperatura ambiente per almeno una settimana prima di utilizzare. </li><li> Piastre seminate sono memorizzati (invertita) in contenitori di plastica sigillati a temperatura ambiente. </li></ol> 4) Il mantenimento di C. elegans Ceppi <ol><li> Per mantenere ben nutrito C. scorte elegans, un verme usano scegliere di spostare tre L4S o adulti gravide di una nuova, testa di serie NGM piastra ogni 3-4 giorni. </li><li> Conservare le piastre (invertito) preferibilmente all&#39;interno di un incubatore a 15 - 22 ° C. Culture in saggi descritti sono stati conservati a 20 ° C. C. sviluppo elegans è dipendente dalla temperatura. Come maintenance temperatura aumenta, il tempo tra fasi di sviluppo diminuisce. </li></ol> 5) Preparazione di Tryptic Soy Agar (TSA) E. faecalis cultura mediatica <ol><li> Per fare 50 piastre, misurare 500 ml di acqua distillata sterile in un pallone e portare ad ebollizione, mescolando, su una piastra. </li><li> Aggiungere 20 g di polvere di agar TSA a pallone e permettere la soluzione di sciogliere. </li><li> Sterilizzare le soluzioni in autoclave a condizioni standard (121 psi, 120 ° C, 20 minuti). </li><li> Lasciar raffreddare la soluzione a 45 ° C in un bagno d&#39;acqua. </li><li> Usando pipette sterili, aggiungere 10 ml di soluzione di agar per ogni polistirolo piastra di Petri di 60 mm. Lasciare i supporti a solidificare a temperatura ambiente per una notte. </li></ol> 6) Preparazione di Tryptic Soy Broth (TSB) E. faecalis cultura mediatica <ol><li> Per fare 250 provette di coltura, misurare 500 ml di acqua distillata sterile in un pallone e caldo su una piastra mescolando. </li&gt; <li> Aggiungere 15 g di agar-agar in polvere TSB al pallone e lasciare che la polvere si dissolva. </li><li> Sterilizzare le soluzioni in autoclave a condizioni standard (121 psi, 120 ° C, 20 minuti). </li><li> Lasciare raffreddare la soluzione a temperatura ambiente, poi pipetta 2 ml in provette, 5 ml sterili. </li></ol> 7) Preparazione di Brain Heart Infusion (BHI) media, con streptomicina, per E. faecalis Cultura <ol><li> Misurare 500 ml di acqua distillata sterile in un pallone e portare ad ebollizione, mescolando, su una piastra. </li><li> Aggiungere 26 g di BHI mezzo al pallone e riportare la soluzione a sciogliere. </li><li> Sterilizzare le soluzioni in autoclave a condizioni standard (121 psi, 120 ° C, 20 minuti). </li><li> Lasciare raffreddare la soluzione a 45 ° C in un bagno d&#39;acqua. </li><li> Usando una tecnica sterile, aggiungere 0,5 ml di una soluzione madre e mescolare streptomicina 10 mg / ml. </li><li> Aggiungere 10 ml della soluzione di polistirene ogni piastra di Petri di 60 mm. </li><li&gt; Consenti supporto a solidificare a temperatura ambiente per una notte. Conservare le piastre (invertito) a 4 ° C fino a poche ore prima dell&#39;uso. </li></ol> 8) Il mantenimento di E. faecalis <ol><li> Per mantenere E. scorte faecalis, usano un&#39;ansa sterile per striatura singole colonie su agar piatti separati di soia triptici (TSA). </li><li> Grow culture a 37 ° C durante la notte. Memorizzare piastre (invertito) in un sacchetto sigillato o scatola a temperatura ambiente per diverse settimane. </li></ol> 9) Preparazione E. Piastre faecalis per EIW Assay <ol><li> Seminare una cultura ml 2 TSB con una colonia di E. faecalis e incubare una notte a 37 ° C. </li><li> Pipettare 20 ml di E. cultura faecalis sul centro di una piastra BHI-streptomicina preparata, e incubare una notte a 37 ° C. </li></ol> 10) Preparazione E. Piastre coli per EIW Assay (placche di comando) <ol><li> Seminare una ml B-bro 100Th cultura con una colonia di E. coli OP50 e incubare una notte a 37 ° C </li><li> Pipettare 20 microlitri della cultura OP50 sul centro di una piastra non seminata NGM e permettono le piastre seminate ad asciugare a temperatura ambiente per una notte. </li></ol> 11) Uovo in Worm Assay <ol><li> Scegli 15 - 20 in scena-L4 C. elegans (Figura 1) sul centro di un prato di batteri su un preparato BHI-Strep-E. Piastra faecalis. Fare attenzione a non trasferire un sacco di OP50 alla piastra BHI. Scegliere lo stesso numero di l4s a un controllo NGM-OP50 piastra. </li><li> Incubare le piastre per 40 ore a 20 ° C. </li><li> Preparare una soluzione di candeggina al 20%. Mescolare un candeggina commerciale (6,0% ipoclorito di sodio) con l&#39;appropriato volume di acqua distillata. </li><li> Aggiungere 10 gocce microlitri di soluzione di candeggina a dieci posizioni distinte su un coperchio di plastica (di un worm o un piatto batterica). </li><li> Utilizzando un piccone verme, trasferire una vite senza fine in ogni goccia di candeggina. Agitare delicatamente la punta delprendere in gocce di candeggina per assicurarsi che il worm ha lavato via la fine del plettro (confermare osservando la goccia sotto un microscopio da dissezione). </li><li> Lasciare che la cuticola di sciogliere per circa 10 minuti o fino a quando i vermi si spalancò, espellendo le uova (Figura 2). Fare attenzione a non trasferire le uova dalla piastra. </li><li> Utilizzando un microscopio da dissezione, contare le uova in ogni goccia di candeggina. </li></ol>

<ol>
	<li>Horvitz, H. R., Chalfie, M., Trent, C., Sulston, J. E., Evans, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serotonin+and+octopamine+in+the+nematode+Caenorhabditis+elegans.">Serotonin and octopamine in the nematode Caenorhabditis elegans.</a> Science. 216, 1012-1014 (1982).</li><li>Sawin, E. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Genetic and cellular analysis of modulated behaviors in Caenorhabditis elegans [dissertation]. , (1996).</li><li>Trent, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Genetic and behavioral studies of the egg-laying system of Caenorhabditis elegans [dissertation]. , (1982).</li><li>Chase, D. L., Koelle, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+analysis+of+RGS+protein+function+in+Caenorhabditis+elegans.">Genetic analysis of RGS protein function in Caenorhabditis elegans.</a> Methods Enzymol. 389, 305-320 (2004).</li><li>Trent, C., Tsuing, N., Horvitz, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Egg-laying+defective+mutants+of+the+nematode+Caenorhabditis+elegans.">Egg-laying defective mutants of the nematode Caenorhabditis elegans.</a> Genetics. 104, 619-647 (1983).</li><li>Weinshenker, D., Garriga, G., Thomas, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+and+pharmacological+analysis+of+neurotransmitters+controlling+egg+laying+in+Caenorhabditis+elegans.">Genetic and pharmacological analysis of neurotransmitters controlling egg laying in Caenorhabditis elegans.</a> J. Neurosci. 15, 6975-6985 (1995).</li><li>Waggoner, L. E., Zhou, G. T., Schafer, R. W., Schafer, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+alternative+behavioral+states+by+serotonin+in+Caenorhabditis+elegans.">Control of alternative behavioral states by serotonin in Caenorhabditis elegans.</a> Neuron. 21, 203-214 (1998).</li><li>Bany, A., Dong, M., Koelle, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+and+cellular+basis+for+acetylcholine+inhibition+of+Caenorhabditis+elegans+egg-laying+behavior.">Genetic and cellular basis for acetylcholine inhibition of Caenorhabditis elegans egg-laying behavior.</a> J. Neurosci. 23, 8060-8069 (2003).</li><li>Dempsey, C. M., Mackenzie, S. M., Gargus, A., Blanco, G., Sze, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serotonin+(5HT),+fluoxetine,+imipramine+and+dopamine+target+distinct+5HT+receptor+signaling+to+modulate+Caenorhabditis+elegans+egg-laying+behavior.">Serotonin (5HT), fluoxetine, imipramine and dopamine target distinct 5HT receptor signaling to modulate Caenorhabditis elegans egg-laying behavior.</a> Genetics. 169, 1425-1436 (2005).</li><li>Leung, M. C., Williams, P. L., Bennedetto, A., Au, C., Helmcke, K. J., Aschner, M., Meyer, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Caenorhabditis+elegans:+an+emerging+model+in+biomedical+and+environmental+toxicology.">Caenorhabditis elegans: an emerging model in biomedical and environmental toxicology.</a> Toxicol. Sci. 106, 5-28 (2008).</li><li>Mylonakis, E., Aballay, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Worms+and+flies+as+genetically+tractable+animal+models+to+study+host-pathogen+interactions.">Worms and flies as genetically tractable animal models to study host-pathogen interactions.</a> Infect. Immun. 73, 3833-3841 (2005).</li><li>Schafer, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> WormBook. , (2005).</li><li>White, J., Southgate, E., Thomson, N., Brenner, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+structure+of+the+Caenorhabditis+elegans+nervous+system.">The structure of the Caenorhabditis elegans nervous system.</a> Philos. Trans. R. Soc. Lond. B. Biol. Sci. 314, 1-340 (1986).</li><li>Desai, C., Garriga, G., McIntire, S. L., Horvitz, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+genetic+pathway+for+the+development+of+the+Caenorhabditis+elegans+HSN+motor+neurons.">A genetic pathway for the development of the Caenorhabditis elegans HSN motor neurons.</a> Nature. 336, 638-646 (1988).</li><li>Garsin, D. A., Sifri, C. D., Mylonakis, E., Qin, X., Singh, K. V., Murray, B. E., Calderwood, S. B., Ausubel, F. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+model+host+for+identifying+Gram-positive+virulence+factors.">A simple model host for identifying Gram-positive virulence factors.</a> Proc. Natl. Acad. Sci. U.S.A. 98, 10892-10897 (2001).</li><li>Aballay, A., Yorgey, P., Ausubel, F. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salmonella+typhmurium+proliferates+and+establishes+a+persistent+infection+in+the+intestine+of+Caenorhabditis+elegans.">Salmonella typhmurium proliferates and establishes a persistent infection in the intestine of Caenorhabditis elegans.</a> Curr. Biol. 10, 1539-1542 (2000).</li><li>O'Quinn, A. L., Wiegand, E. M., Jeddeloh, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Burkholderia+pseudomallei+kills+the+nematode+Caenorhabditis+elegans+using+an+endotoxin-mediated+paralysis.">Burkholderia pseudomallei kills the nematode Caenorhabditis elegans using an endotoxin-mediated paralysis.</a> Cell. Microbiol. 3, 381-393 (2001).</li><li>Brenner, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetics+of+Caenorhabditis+elegans.">Genetics of Caenorhabditis elegans.</a> Genetics. 77, 71-94 (1974).</li><li>Harvey, S. C., Shorto, A., Orbidans, H. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+genetic+analysis+of+life-+history+traits+of+Caenorhabditis+elegans+in+stressful+environments.">Quantitative genetic analysis of life- history traits of Caenorhabditis elegans in stressful environments.</a> BMC Evol. Biol. 8, 15 (2008).</li><li>Harvey, S. C., Orbidans, H. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=All+eggs+are+not+equal:+the+maternal+environment+affects+progeny+reproduction+and+developmental+fate+in+Caenorhabditis+elegans.">All eggs are not equal: the maternal environment affects progeny reproduction and developmental fate in Caenorhabditis elegans.</a> PLoS One. 6, e25840 (2011).</li><li>Klass MR, . <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aging+in+the+nematode+Caenorhabditis+elegans:+major+biological+and+environmental+factors+influencing+life+span.">Aging in the nematode Caenorhabditis elegans: major biological and environmental factors influencing life span.</a> Mech. Ageing. Dev. 6, 413-429 (1977).</li></ol>

Gli autori dichiarano di non avere interessi finanziari in competizione.

Le fasi più critiche eseguire con successo questo saggio sono: 1) utilizzando grammature ben nutriti di C. elegans, 2) coltivazione di singoli tipi di batteri sulla piastra saggio, 3) identificare accuratamente messo in scena L4 vermi per l&#39;esposizione a E. faecalis, 4) tenere il tempo di esposizione a E. faecalis coerente in tutte le prove e le 5) Tempo di sbiancanti non dovrebbe superare i dieci minuti per evitare la disintegrazione uovo. Per questo dosaggio...

Caenorhabditis elegans, un microscopico, nematodi a vita libera, è un organismo modello tradizionalmente utilizzato per lo studio dello sviluppo delle cellule e dei processi di segnalazione per la sua anatomia trasparente, sviluppo ben caratterizzato, completamente sequenziato genoma, la generazione in tempo breve, e omologia genetica per l&#39;uomo . Più recentemente, C. elegans è diventato un organismo modello nel campo della tossicologia ambientale e di immunità innata 10, 11. Questi auto-fertilizzanti vermi ermafroditi diventano sessualmente maturi entro due o tre giorni di cova dall&#39;uovo. Durante il suo ciclo di vita, C. elegans passa attraverso quattro stadi larvali (L1-L4), prima di raggiungere l&#39;età adulta. Un isolato ermafrodita in grado di produrre, in media, 300 prole entro tre giorni di picco di fecondità. In riproduttivamente maturo C. elegans ermafroditi, uova fecondate vengono mantenuti all&#39;interno dell&#39;utero per diverse ore prima di essere licenziati. Glinormale numero di uova memorizzati in utero in qualsiasi momento (durante l&#39;alta fecondità) è tra i dieci ei quindici 12. Il numero di uova in utero è funzione sia del tasso di produzione di uova e il tasso di deposizione. Uova fecondate vengono espulsi dall&#39;utero dalla contrazione dei muscoli sedici vulval disposti intorno all&#39;apertura della vulva 13. Motoneuroni Ermafrodito-specifici (HSN di) e motoneuroni VC sinapsi sui muscoli vulvari influenzano la contrazione muscolare e quindi la deposizione delle uova comportamento 5,7,13,14. Espulsione di uova dal dell&#39;utero si verifica a causa di attività coordinata dei neuroni e muscoli. Culture Lab di C. elegans sono allevati con una dieta di non patogeno Escherichia coli OP50. In ambiente naturale, C. elegans entrano in contatto con una varietà di fonti di cibo, come batteri patogeni, che possono essere potenzialmente dannosi. Quando esposti a sostanze nocive inl&#39;ambiente, C. elegans conservano le uova fino a quando l&#39;ambiente diventa più favorevole. Presumibilmente questo ritenzione uovo è uno sforzo per proteggere la loro progenie. In questo uovo a vite senza fine (EIW) saggio, C. elegans sono esposti ai batteri potenzialmente patogeni, Enterococcus faecalis, che si trova nell&#39;ambiente. L&#39;esposizione a forme patogeni di E. faecalis possono causare infezione intestinale persistente e persino la morte in C. elegans 15. Esposizione ad altre forme di batteri patogeni hanno mostrato di influenzare la ritenzione dell&#39;uovo 16,17, tuttavia l&#39;effetto non è stato quantificato. Inoltre, l&#39;effetto di lieve patogeni ceppi di E. faecalis, i ceppi che non sono immediatamente letale, sul comportamento delle uova non è stato studiato. Saggi EIW coinvolgono contando il numero di uova trattenuto nell&#39;utero di C. elegans 4. Anche se C. eleganssono trasparenti, le uova si accumulano in utero possono essere difficili da quantificare in un animale intatto. Il saggio EIW coinvolge lo sbiancamento gravido adulto C. elegans che sono stati esposti ai batteri per un determinato periodo di tempo. La soluzione di candeggina scioglie la cuticola esterna lasciando dietro di sé le uova. Le uova sono refrattiva agli effetti della candeggina per la presenza di un guscio protettivo. Dopo sbianca, uno è molto facilmente in grado di contare il numero di uova rilasciate dall&#39;utero dei vermi su di imbianchimento. Il saggio descritto è un metodo semplice, economico e rapido per quantificare il numero di uova in utero in una sola volta, e quindi quantificare gli effetti di E. faecalis sulla ritenzione dell&#39;uovo. Il test può essere utilizzato per quantificare l&#39;effetto di altri tipi di batteri, tossine ambientali o farmaci sulla ritenzione uovo. Questa analisi ha anche il potenziale per essere utilizzato come schermo per la patogenicità batterica.

<table border="0" cellpadding="0" cellspacing="0" width="2472">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Agar, ultrapure</td>
			<td style="width:191px;">Affymetrix</td>
			<td style="width:119px;">10906</td>
			<td style="width:1791px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Bacto Peptone</td>
			<td style="width:191px;">Becton Dickinson</td>
			<td style="width:119px;">211677</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Bacto Tryptone</td>
			<td style="width:191px;">Becton Dickinson</td>
			<td style="width:119px;">211705</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Brain Heart Infusion dehydrated medium</td>
			<td style="width:191px;">Carolina Biological Supply</td>
			<td style="width:119px;">781781</td>
			<td></td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:371px;">C. elegans, N2 strain</td>
			<td style="width:191px;">Caenorhabditis Genetics Center</td>
			<td style="width:119px;"></td>
			<td>http://www.cbs.umn.edu/cgc</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:371px;">Cholesterol</td>
			<td style="width:191px;">Alfa Aesar</td>
			<td style="width:119px;">A11470</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Culture plates for C. elegans</td>
			<td style="width:191px;">Tritech Research Inc.</td>
			<td style="width:119px;">T3308</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:371px;">Culture plates for E. faecalis</td>
			<td style="width:191px;">Fisher Scientific-Fisherbrand</td>
			<td style="width:119px;">875713</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:371px;">E. coli (OP50)</td>
			<td style="width:191px;">Caenorhabditis Genetics Center</td>
			<td style="width:119px;"></td>
			<td>http://www.cbs.umn.edu/cgc</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">E. faecalis strains</td>
			<td style="width:191px;"></td>
			<td style="width:119px;"></td>
			<td>provided by J. Middleton. All isolates were confirmed as enterococci</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;"></td>
			<td style="width:191px;"></td>
			<td style="width:119px;"></td>
			<td>by observing growth on enterococcosel agar (BBL) and in 6% NaCl broth;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;"></td>
			<td style="width:191px;"></td>
			<td style="width:119px;"></td>
			<td>
			all strains grew at 44.5 &#186;C and were catalase negative and hydrolyzed esculin. A simplified&#160;dichotomous key based on pigmentation and fermentation reactions for six sugars&#160;(arabinose, mannitol, methyl-&#945;-D-glucopyranoside (MGP), ribose, sorbose and sorbitol) allowed&#160;presumptive identification of all E. faecalis strains (Efs lacks pigmentation and is arabinose, MGP&#160;and sorbose negative and sorbitol, mannitol and ribose positive). All presumptive Efs strains&#160;were confirmed using the API 20 STREP system (Biomerieux).
			</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;"></td>
			<td style="width:191px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;"></td>
			<td style="width:191px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;"></td>
			<td style="width:191px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;"></td>
			<td style="width:191px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;"></td>
			<td style="width:191px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Microscope</td>
			<td style="width:191px;">Motic</td>
			<td style="width:119px;">SMZ 168B</td>
			<td>any microscope with transmitted illumination and 50X magnification should be sufficient</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Streptomycin sulfate</td>
			<td style="width:191px;">Fisher BioReagents</td>
			<td style="width:119px;">BP910-50</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:371px;">Tryptic Soy Agar (Soybean-Casein Digest Agar Medium), Difco</td>
			<td style="width:191px;">Becton Dickinson</td>
			<td style="width:119px;">236950</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:371px;">Trypticase Soy Broth (Soybean-Casein Digest Medium), BBL</td>
			<td style="width:191px;">Becton Dickinson</td>
			<td style="width:119px;">211768</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:371px;">Yeast extract</td>
			<td style="width:191px;">Acros</td>
			<td style="width:119px;">61180-1000</td>
			<td></td>
		</tr>
	</tbody>
</table>

measuring the effects of bacteria on c. elegans behavior using an egg retention assay

C. elegans comportamento di deposizione delle uova è influenzato da stimoli ambientali come osmolarità 1 e vibrazioni 2. In totale assenza di cibo C. elegans cessano anche ovodeposizione e conservano le uova fecondate nel loro utero 3. Tuttavia, l&#39;effetto di diverse fonti alimentari, in particolare i batteri patogeni e in particolare Enterococcus faecalis, sul comportamento ovodeposizione non è ben caratterizzata. L&#39;uovo-a-vite senza fine (EIW) saggio è uno strumento utile per quantificare gli effetti di diversi tipi di batteri, in questo caso E. faecalis, il comportamento di deposizione delle uova. Saggi EIW coinvolgono contando il numero di uova trattenuto nell&#39;utero di C. elegans 4. Il saggio EIW coinvolge lo sbiancamento in scena, gravido adulto C. elegans per rimuovere la cuticola e separare le uova trattenuti dal animale. Prima di sbianca, vermi sono esposti a batteri (o qualsiasi tipo di stimolo ambientale) Per un determinato periodo di tempo. Dopo lo sbiancamento, uno è molto facilmente in grado di contare il numero di uova trattenuti all&#39;interno dell&#39;utero dei vermi. In questo saggio, un incremento quantificabile in ritenzione di uova dopo la E. esposizione faecalis può essere facilmente misurato. Il saggio è un saggio EIW comportamentale che può essere usato per individuare batteri potenzialmente patogeni o la presenza di tossine ambientali. Inoltre, il saggio EIW può essere uno strumento per lo screening per i farmaci che influenzano neurotrasmettitore segnalazione dal comportamento di deposizione delle uova è modulato da neurotrasmettitori come la serotonina e acetilcolina 5-9.

Questo test permette di quantificare il numero di uova trattenuti all&#39;interno C. elegans dopo esposizione a E. faecalis. L4 scena vermi (caratterizzati da trasparente spazi al di sopra loro vulva, Figura 1) sono stati esposti a E. faecalis fino all&#39;età adulta. Dopo 40 ore di esposizione a E. faecalis, lo sbiancamento è stata eseguita. Come la cuticola disintegrato nel droplet candeggina, le uova divennero più evidenti (Figura 2). Il numero ...

Watch this Scientific Journal Video about Measuring the Effects of Bacteria on C. Elegans Behavior Using an Egg Retention Assay at JoVE.com

Measuring the Effects of Bacteria on C. Elegans Behavior Using an Egg Retention Assay | Biology | Video

Measuring the Effects of Bacteria on C. Elegans Behavior Using an Egg Retention Assay

Un uovo-in-worm (EIW) saggio è un metodo utile per quantificare la deposizione delle uova comportamento. Alterazioni nella deposizione delle uova può essere una risposta comportamentale del modello di organismo<em&gt; Caenorhabditis elegans</em&gt; A sostanze ambientali potenzialmente nocivi come quelli prodotti da batteri patogeni.

Misurare gli effetti dei batteri su<em&gt; C. Elegans</em&gt; Comportamento utilizzando un saggio di ritenzione dell&#39;uovo

C. elegans egg-laying behavior is  affected by environmental cues such as osmolarity1 and  vibration2. In the total absence of food C. elegans also cease ...

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Measuring the Effects of Bacteria on C. Elegans Behavior Using an Egg Retention Assay

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16.9K Views.  Fairleigh Dickinson University. Un uovo-in-worm (EIW) saggio è un metodo utile per quantificare la deposizione delle uova comportamento. Alterazioni nella deposizione delle uova può essere una risposta comportamentale del modello di organismo Caenorhabditis elegans A sostanze ambientali potenzialmente nocivi come quelli prodotti da batteri patogeni.

Video: Measuring the Effects of Bacteria on C. Elegans Behavior Using an Egg Retention Assay

Generation of Stable Transgenic C. elegans Using Microinjection

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1. The plasmid DNA rearranges to form extrachromosomal concatamers that are stably inherited, though not with the same efficiency as actual chromosomes 2. A gene of interest is co-injected with an obvious phenotypic marker, such as rol-6 or GFP, to allow selection of transgenic animals under a dissecting microscope. The exogenous gene may be expressed from its native promoter for cellular localization studies. Alternatively, the transgene can be driven by a different tissue-specific promoter to assess the role of the gene product in that particular cell or tissue. This technique efficiently drives gene expression in all tissues of C. elegans except for the germline or early embryo 3. Creation of transgenic animals is widely utilized for a range of experimental paradigms. This video demonstrates the microinjection procedure to generate transgenic worms. Furthermore, selection and maintenance of stable transgenic C. elegans lines is described.

This video demonstrates the technique of microinjection into the gonad of C. elegans to create transgenic animals.

Generazione di Stabile transgenici C. elegans Utilizzando Microiniezione

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1.  The plasmid DNA rearranges to ...

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Biologia

Measuring Caenorhabditis elegans Life Span on Solid Media

Aging is a degenerative process characterized by a progressive deterioration of cellular components and organelles resulting in mortality. The nematode Caenorhabditis elegans has emerged as a principal model used to study the biology of aging. Because virtually every biological subsystem undergoes functional decline with increasing age, life span is the primary endpoint of interest when considering total rate of aging. In nematodes, life span is typically defined as the number of days an animal remains responsive to external stimuli. Nematodes can be propagated either in liquid media or on solid media in plates, and techniques have been developed for measuring life span under both conditions. Here we present a generalized protocol for measuring life span of nematodes maintained on solid nematode growth media and fed a diet of UV-killed bacteria. These procedures can easily be adapted to assay life span under various common conditions, including a diet consisting of live bacteria, dietary restriction, and RNA interference.

Measuring Caenorhabditis elegans Life Span on Solid Media

In this article we present a general protocol for measuring life span of nematodes maintained on solid media with UV-killed bacterial food.

Misura Caenorhabditis elegans Life Span su terreni solidi

Aging is a degenerative process characterized by a progressive deterioration of cellular components and organelles resulting in mortality. The nematode ...

Imaging C. elegans Embryos using an Epifluorescent Microscope and Open Source Software

Cellular processes, such as chromosome assembly, segregation and cytokinesis,are inherently dynamic. Time-lapse imaging of living cells, using fluorescent-labeled reporter proteins or differential interference contrast (DIC) microscopy, allows for the examination of the temporal progression of these dynamic events which is otherwise inferred from analysis of fixed samples1,2. Moreover, the study of the developmental regulations of cellular processes necessitates conducting time-lapse experiments on an intact organism during development. The Caenorhabiditis elegans embryo is light-transparent and has a rapid, invariant developmental program with a known cell lineage3, thus providing an ideal experiment model for studying questions in cell biology4,5and development6-9. C. elegans is amendable to genetic manipulation by forward genetics (based on random mutagenesis10,11) and reverse genetics to target specific genes (based on RNAi-mediated interference and targeted mutagenesis12-15). In addition, transgenic animals can be readily created to express fluorescently tagged proteins or reporters16,17. These traits combine to make it easy to identify the genetic pathways regulating fundamental cellular and developmental processes in vivo18-21. In this protocol we present methods for live imaging of C. elegans embryos using DIC optics or GFP fluorescence on a compound epifluorescent microscope. We demonstrate the ease with which readily available microscopes, typically used for fixed sample imaging, can also be applied for time-lapse analysis using open-source software to automate the imaging process.

Imaging C. elegans Embryos using an Epifluorescent Microscope and Open Source Software

The C. elegans embryo is a powerful system for studying cell biology and development. We present a protocol for live imaging of C. elegans embryos utilizing DIC optics or fluorescence using readily available epifluorescent microscopes and open-source software.

Imaging C. elegans Gli embrioni utilizzando un microscopio epifluorescente e Software Open Source

Cellular processes, such as chromosome assembly, segregation and cytokinesis,are inherently dynamic. Time-lapse imaging of living cells, using ...

Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase (COX/SDH) Double-labeling Histochemistry

Mitochondrial DNA (mtDNA) defects are an important cause of disease and may underlie aging and aging-related alterations 1,2. The mitochondrial theory of aging suggests a role for mtDNA mutations, which can alter bioenergetics homeostasis and cellular function, in the aging process 3. A wealth of evidence has been compiled in support of this theory 1,4, an example being the mtDNA mutator mouse 5; however, the precise role of mtDNA damage in aging is not entirely understood 6,7.
Observing the activity of respiratory enzymes is a straightforward approach for investigating mitochondrial dysfunction. Complex IV, or cytochrome c oxidase (COX), is essential for mitochondrial function. The catalytic subunits of COX are encoded by mtDNA and are essential for assembly of the complex (Figure 1). Thus, proper synthesis and function are largely based on mtDNA integrity 2. Although other respiratory complexes could be investigated, Complexes IV and II are the most amenable to histochemical examination 8,9. Complex II, or succinate dehydrogenase (SDH), is entirely encoded by nuclear DNA (Figure 1), and its activity is typically not affected by impaired mtDNA, although an increase might indicate mitochondrial biogenesis 10-12. The impaired mtDNA observed in mitochondrial diseases, aging, and age-related diseases often leads to the presence of cells with low or absent COX activity 2,12-14. Although COX and SDH activities can be investigated individually, the sequential double-labeling method 15,16 has proved to be advantageous in locating cells with mitochondrial dysfunction 12,17-21.
Many of the optimal constitutions of the assay have been determined, such as substrate concentration, electron acceptors/donors, intermediate electron carriers, influence of pH, and reaction time 9,22,23. 3,3'-diaminobenzidine (DAB) is an effective and reliable electron donor 22. In cells with functioning COX, the brown indamine polymer product will localize in mitochondrial cristae and saturate cells 22. Those cells with dysfunctional COX will therefore not be saturated by the DAB product, allowing for the visualization of SDH activity by reduction of nitroblue tetrazolium (NBT), an electron acceptor, to a blue formazan end product 9,24. Cytochrome c and sodium succinate substrates are added to normalize endogenous levels between control and diseased/mutant tissues 9. Catalase is added as a precaution to avoid possible contaminating reactions from peroxidase activity 9,22. Phenazine methosulfate (PMS), an intermediate electron carrier, is used in conjunction with sodium azide, a respiratory chain inhibitor, to increase the formation of the final reaction products 9,25. Despite this information, some critical details affecting the result of this seemly straightforward assay, in addition to specificity controls and advances in the technique, have not yet been presented.

Visualization of Mitochondrial Respiratory Function using Cytochrome C Oxidase / Succinate Dehydrogenase COX/SDH Double-labeling Histochemistry

The cytochrome c oxidase/sodium dehydrogenase (COX/SDH) double-labeling method allows for direct visualization of mitochondrial respiratory enzyme deficiencies in fresh-frozen tissue sections. This is a straightforward histochemical technique and is useful in investigating mitochondrial diseases, aging, and aging-related disorders.

Visualizzazione della funzione respiratoria mitocondriale utilizzando Citocromo C Ossidasi / succinato deidrogenasi (COX / SDH) Doppio etichettatura Istochimica

Mitochondrial DNA (mtDNA) defects are an important cause of disease and may underlie aging and aging-related alterations 1,2. The mitochondrial theory of ...

Creating Defined Gaseous Environments to Study the Effects of Hypoxia on C. elegans

Oxygen is essential for all metazoans to survive, with one known exception1. Decreased O2 availability (hypoxia) can arise during states of disease, normal development or changes in environmental conditions2-5. Understanding the cellular signaling pathways that are involved in the response to hypoxia could provide new insight into treatment strategies for diverse human pathologies, from stroke to cancer. This goal has been impeded, at least in part, by technical difficulties associated with controlled hypoxic exposure in genetically amenable model organisms.
The nematode Caenorhabditis elegans is ideally suited as a model organism for the study of hypoxic response, as it is easy to culture and genetically manipulate. Moreover, it is possible to study cellular responses to specific hypoxic O2 concentrations without confounding effects since C. elegans obtain O2 (and other gasses) by diffusion, as opposed to a facilitated respiratory system6. Factors known to be involved in the response to hypoxia are conserved in C. elegans. The actual response to hypoxia depends on the specific concentration of O2 that is available. In C. elegans, exposure to moderate hypoxia elicits a transcriptional response mediated largely by hif-1, the highly-conserved hypoxia-inducible transcription factor6-9. C .elegans embryos require hif-1 to survive in 5,000-20,000 ppm O27,10. Hypoxia is a general term for "less than normal O2". Normoxia (normal O2) can also be difficult to define. We generally consider room air, which is 210,000 ppm O2 to be normoxia. However, it has been shown that C. elegans has a behavioral preference for O2 concentrations from 5-12% (50,000-120,000 ppm O2)11. In larvae and adults, hif-1 acts to prevent hypoxia-induced diapause in 5,000 ppm O212. However, hif-1 does not play a role in the response to lower concentrations of O2 (anoxia, operational definition &lt;10 ppm O2)13. In anoxia, C. elegans enters into a reversible state of suspended animation in which all microscopically observable activity ceases10. The fact that different physiological responses occur in different conditions highlights the importance of having experimental control over the hypoxic concentration of O2.
Here, we present a method for the construction and implementation of environmental chambers that produce reliable and reproducible hypoxic conditions with defined concentrations of O2. The continual flow method ensures rapid equilibration of the chamber and increases the stability of the system. Additionally, the transparency and accessibility of the chambers allow for direct visualization of animals being exposed to hypoxia. We further demonstrate an effective method of harvesting C. elegans samples rapidly after exposure to hypoxia, which is necessary to observe many of the rapidly-reversed changes that occur in hypoxia10,14. This method provides a basic foundation that can be easily modified for individual laboratory needs, including different model systems and a variety of gasses.

Creating Defined Gaseous Environments to Study the Effects of Hypoxia on C. elegans

This paper details how to use continuous-flow hypoxia chambers to generate atmospheres with defined concentrations of O2 to understand biological responses to decreased O2. This system is easy to setup and maintain, and flexible enough to suit a wide range of O2 concentrations and model systems

La creazione di ambienti definiti gassosi Per studiare gli effetti dell&#39;ipossia sulla<em&gt; C. elegans</em

Oxygen is essential for all metazoans to survive, with one known exception1. Decreased O2 availability (hypoxia) can arise during states of disease, ...

An Explant Assay for Assessing Cellular Behavior of the Cranial Mesenchyme

The central nervous system is derived from the neural plate that undergoes a series of complex morphogenetic movements resulting in formation of the neural tube in a process known as neurulation. During neurulation, morphogenesis of the mesenchyme that underlies the neural plate is believed to drive neural fold elevation. The cranial mesenchyme is comprised of the paraxial mesoderm and neural crest cells. The cells of the cranial mesenchyme form a pourous meshwork composed of stellate shaped cells and intermingling extracellular matrix (ECM) strands that support the neural folds. During neurulation, the cranial mesenchyme undergoes stereotypical rearrangements resulting in its expansion and these movements are believed to provide a driving force for neural fold elevation. However, the pathways and cellular behaviors that drive cranial mesenchyme morphogenesis remain poorly studied. Interactions between the ECM and the cells of the cranial mesenchyme underly these cell behaviors. Here we describe a simple ex vivo explant assay devised to characterize the behaviors of these cells. This assay is amendable to pharmacological manipulations to dissect the signaling pathways involved and live imaging analyses to further characterize the behavior of these cells. We present a representative experiment demonstrating the utility of this assay in characterizing the migratory properties of the cranial mesenchyme on a variety of ECM components.

The cranial mesenchyme undergoes dramatic morphogenic movements that likely provides a driving force for elevation of the neural folds1,2. Here we describe a simple ex vivo explant assay to characterize the cellular behaviors of the cranial mesenchyme during neurulation. This assay has numerous applications including being amenable to pharmacological manipulations and live imaging analyses.

Un test per la valutazione dei comportamenti Espianto cellulare del Mesenchima cranio

The central nervous system is derived from the neural plate that undergoes a series of complex morphogenetic movements resulting in formation of the ...

C. elegans Chemotaxis Assay

Many organisms use chemotaxis to seek out food sources, avoid noxious substances, and find mates. Caenorhabditis elegans has impressive chemotaxis behavior.
 The premise behind testing the response of the worms to an odorant is to place them in an area and observe the movement evoked in response to an odorant. Even with the many available assays, optimizing worm starting location relative to both the control and test areas, while minimizing the interaction of worms with each other, while maintaining a significant sample size remains a work in progress 1-10. The method described here aims to address these issues by modifying the assay developed by Bargmann et al.1. A Petri dish is divided into four quadrants, two opposite quadrants marked "Test" and two are designated "Control". Anesthetic is placed in all test and control sites. The worms are placed in the center of the plate with a circle marked around the origin to ensure that non-motile worms will be ignored. Utilizing a four-quadrant system rather than one 2 or two 1 eliminates bias in the movement of the worms, as they are equidistant from test and control samples, regardless of which side of the origin they began. This circumvents the problem of worms being forced to travel through a cluster of other worms to respond to an odorant, which can delay worms or force them to take a more circuitous route, yielding an incorrect interpretation of their intended path. This method also shows practical advantages by having a larger sample size and allowing the researcher to run the assay unattended and score the worms once the allotted time has expired.

C. elegans Chemotaxis Assay

A method of quantitatively evaluating the chemotactic response of Caenorhabditis elegans is described. A chemotactic index (CI) was employed as a way to precisely evaluate the response of worms to certain targets, and serve as a platform of comparison between strains and compounds of interest.

C. elegans Chemiotassi Assay

Many organisms use chemotaxis to seek out food sources, avoid noxious substances, and find mates.  Caenorhabditis elegans has impressive chemotaxis ...

Antibody Staining in C. Elegans Using &quot;Freeze-Cracking&quot;

To stain C. elegans with antibodies, the relatively impermeable cuticle must be bypassed by chemical or mechanical methods. "Freeze-cracking" is one method used to physically pull the cuticle from nematodes by compressing nematodes between two adherent slides, freezing them, and pulling the slides apart. Freeze-cracking provides a simple and rapid way to gain access to the tissues without chemical treatment and can be used with a variety of fixatives. However, it leads to the loss of many of the specimens and the required compression mechanically distorts the sample. Practice is required to maximize recovery of samples with good morphology. Freeze-cracking can be optimized for specific fixation conditions, recovery of samples, or low non-specific staining, but not for all parameters at once. For antibodies that require very hard fixation conditions and tolerate the chemical treatments needed to chemically permeabilize the cuticle, treatment of intact nematodes in solution may be preferred. If the antibody requires a lighter fix or if the optimum fixation conditions are unknown, freeze-cracking provides a very useful way to rapidly assay the antibody and can yield specific subcellular and cellular localization information for the antigen of interest.

Antibody Staining in C. Elegans Using &quot;Freeze-Cracking&quot;

"Freeze-cracking," a method for exposing the inner tissues of the nematode C. elegans to antibodies for protein localization, is demonstrated.

Antibody colorazione in<em&gt; C. Elegans</em&gt; Uso di &quot;Freeze-Cracking&quot;

To stain C.  elegans with antibodies, the relatively impermeable cuticle must be  bypassed by chemical or mechanical methods.  "Freeze-cracking" is one ...

Large-scale Gene Knockdown in C. elegans Using dsRNA Feeding Libraries to Generate Robust Loss-of-function Phenotypes

RNA interference by feeding worms bacteria expressing dsRNAs has been a useful tool to assess gene function in C. elegans. While this strategy works well when a small number of genes are targeted for knockdown, large scale feeding screens show variable knockdown efficiencies, which limits their utility. We have deconstructed previously published RNAi knockdown protocols and found that the primary source of the reduced knockdown can be attributed to the loss of dsRNA-encoding plasmids from the bacteria fed to the animals. Based on these observations, we have developed a dsRNA feeding protocol that greatly reduces or eliminates plasmid loss to achieve efficient, high throughput knockdown. We demonstrate that this protocol will produce robust, reproducible knock down of C. elegans genes in multiple tissue types, including neurons, and will permit efficient knockdown in large scale screens. This protocol uses a commercially available dsRNA feeding library and describes all steps needed to duplicate the library and perform dsRNA screens. The protocol does not require the use of any sophisticated equipment, and can therefore be performed by any C. elegans lab.

Large-scale Gene Knockdown in C. elegans Using dsRNA Feeding Libraries to Generate Robust Loss-of-function Phenotypes

While dsRNA feeding in C. elegans is a powerful tool to assess gene function, current protocols for large scale feeding screens result in variable knockdown efficiencies. We describe an improved protocol for performing large scale RNAi feeding screens that results in highly efficacious and reproducible knockdown of gene expression.

Su larga scala Knockdown Gene in<em&gt; C. elegans</em&gt; Utilizzo di librerie di alimentazione dsRNA per generare fenotipi Robusti Perdita di funzione

RNA interference by feeding worms bacteria expressing dsRNAs has been a useful tool to assess gene function in C. elegans. While this strategy works well ...

An Anoxia-starvation Model for Ischemia/Reperfusion in C. elegans

Protocols for anoxia/starvation in the genetic model organism C. elegans simulate ischemia/reperfusion. Worms are separated from bacterial food and placed under anoxia for 20 hr&#160;(simulated ischemia), and subsequently moved to a normal atmosphere with food (simulated reperfusion). This experimental paradigm results in increased death and neuronal damage, and techniques are presented to assess organism viability, alterations to the morphology of touch neuron processes, as well as touch sensitivity, which represents the behavioral output of neuronal function. Finally, a method for constructing hypoxic incubators using common kitchen storage containers is described. The addition of a mass flow control unit allows for alterations to be made to the gas mixture in the custom incubators, and a circulating water bath allows for both temperature control and makes it easy to identify leaks. This method provides a low cost alternative to commercially available units.

An Anoxia-starvation Model for Ischemia/Reperfusion in C. elegans

A protocol is described that uses anoxia/starvation in C. elegans to model ischemia/reperfusion. Functional outcomes include increased mortality, visible abnormalities in GFP-labeled neuronal processes, and impaired behavioral responses that require neuronal function.

Un modello di anossia-fame per ischemia / riperfusione in<em&gt; C. elegans</em

Protocols for anoxia/starvation in the genetic model organism C. elegans simulate ischemia/reperfusion. Worms are separated from bacterial food and placed ...